By 202380261
Discussion
I. DEFINITION AND SCOPE
B. SCOPE OF TOXICOLOGY
➤ describe an important molecular event in the cascade of events leading from exposure to toxicity.
a. Toxicity at the biochemical and molecular levels
➤ include enzymes that metabolize xenobiotics, generation of reactive intermediates, interaction of xenobiotics or their metabolites with macromolecules, gene expression and signaling pathways. b. Effects of toxicants on animal and human behavior
➤ involves both the peripheral and central nervous systems, as well as effects mediated by other organ systems, such as the endocrine glands.
d. Carcinogenesis c. Effects of diet on the expression of toxicity
➤ includes the chemical, biochemical, and molecular events that lead to the large number of effects on cell growth e. Teratogenesis
➤ includes the chemical, biochemical, and molecular events that lead to deleterious effects on development.
f. Mutagenesis
➤ toxic effects on the genetic material and the inheritance of these effects.
g. Organ toxicity
➤ effects at the level of organ function - neurotoxicity, hepatotoxicity, and nephrotoxicity.
➤ answer certain critically important questions: Is the substance likely to be toxic? What is its chemical identity? How much of it is present? How can we assay its toxic effect, and what is the minimum level at which this toxic effect can be detected?
➤ Toxicity testing involves the use of living systems to estimate toxic effects. It covers the range of tests (bioassays) from short-term tests for genotoxicity such as the Ames test and cell culture techniques to the use of intact animals for a variety of tests from acute toxicity to lifetime chronic toxicity.